This proposal aims to develop a robust and ultra high-throughput technology for simultaneously assaying methylation at many specific sites in a genome. The technology we aim to develop will be based on a beadbased optical fiber array platform. This system is capable of analyzing hundreds to thousands of samples per day, and performing more than a million methylation measurements per instrument per day. We aim to provide a system that will enable high-resolution methylation profiling in large numbers of samples. The technology developed in this proposal will provide a powerful tool not only for fundamental genomic research, but also for cancer biologystudies, with potential application to cancer classification and diagnosis, and anti-cancer drug target identification and drug screening. [unreadable] [unreadable] [unreadable] [unreadable]